Content viewing and editing applications such as web browsers and similar applications are used to present structured documents, such as webpages and other HTML files, to a user via a display interface of an electronic device. Typically, the application parses one or more input files including the structured document, such as a webpage—which may be retrieved from local storage at the electronic device, or alternatively received over a network connection from a network resource—to render the input file as a rendered document for display on a display screen of the electronic device. The structured document itself may include a number of different content elements, such as images, text, hyperlinks, embedded multimedia components, and metadata, many of which may be visible when the rendered document is displayed. The presence of different elements in the structured document thus increases the processing time required to prepare the render document for display.
In a portable electronic device such as a smartphone or tablet, the display area available on the device's display screen limits the amount of content that can be displayed on the screen at a given time, potentially resulting in a cluttered view of a structured document containing many elements. Further, those portable electronic devices having an integrated display screen may be usable in more than one orientation, such as a landscape orientation mode and a portrait orientation mode, which typically have different screen proportions, thus affecting the appearance of the rendered document displayed on the screen.